Algae laminite

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Fine-layered sedimentary rock ("wrinkle marks") in the southern part of Gotland Island .

Algae laminite ("laminite" from Latin lāmina "plate, sheet, disc") is a finely layered sedimentary rock with narrow structures, which was created by the metabolic activity of algae and other microbes as well as by the binding of carbonate particles in the microbe mats (formerly: algae mats).

Emergence

Algae laminites are similar to stromatolites in terms of their method of formation and are basically comparable to them. Some microorganisms in the shallow water areas of seas and lakes build up their own lifelike space through the excretion of mineral metabolic products (carbonates, silicic acid) . The corals , for example, are particularly well-known for this . Others bind mineral suspended matter into their habitat.
Fine-layered for the emergence of planar or slightly curled laminite are mainly cyanobacteria responsible. Biomicritical carbonate particles from the suspended matter content of the water are incorporated in their mat-shaped cultures . The microbes continue to grow perpendicular to the mat plane and in this way create a systematically recurring layer-like structure. The parallel position of these layers located at a short distance from one another is particularly characteristic.

Petrified gas bubbles (“birdseyes” or syngeneic pores) can be found embedded in the fine layers, which can subsequently be filled with mineral substances.

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